Fix response history limit ordering

Retain the newest history items when local response providers apply a limit, and add regression coverage for both in-memory and file-backed storage.\n\nCo-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: Shivakishore14

sdk/agentserver/azure-ai-agentserver-responses/CHANGELOG.md

@@ -22,6 +22,7 @@
 ### Bugs Fixed
 
 - Restored JSON-string encoding for response-level `internal_metadata` so resilient response checkpoints round-trip through Foundry storage.
+- Fixed local response providers to retain the newest conversation history items when applying the history limit.
 
 ### Other Changes
 

sdk/agentserver/azure-ai-agentserver-responses/azure/ai/agentserver/responses/store/_file.py

@@ -579,7 +579,7 @@ async def get_history_item_ids(
 
             if limit <= 0:
                 return []
-            return resolved[:limit]
+            return resolved[-limit:]
 
     # ------------------------------------------------------------------
     # Internal helpers (must be called with self._lock held)

sdk/agentserver/azure-ai-agentserver-responses/azure/ai/agentserver/responses/store/_memory.py

@@ -325,7 +325,7 @@ async def get_history_item_ids(
 
             if limit <= 0:
                 return []
-            return resolved[:limit]
+            return resolved[-limit:]
 
     async def create_execution(self, execution: ResponseExecution, *, ttl_seconds: int | None = None) -> None:
         """Create a new execution and replay container for ``execution.response_id``.

sdk/agentserver/azure-ai-agentserver-responses/tests/unit/test_file_response_store_parity.py

@@ -327,7 +327,7 @@ async def test_history_respects_limit(tmp_path: Path) -> None:
             history_item_ids=["hist1", "hist2"],
         )
         ids = await provider.get_history_item_ids("r_prev", None, limit=3)
-        assert ids == ["hist1", "hist2", "in1"]
+        assert ids == ["out1", "out2", "out3"]
         # Non-positive limit returns empty.
         ids_zero = await provider.get_history_item_ids("r_prev", None, limit=0)
         assert ids_zero == []

sdk/agentserver/azure-ai-agentserver-responses/tests/unit/test_in_memory_provider_crud.py

@@ -373,7 +373,7 @@ def test_history__respects_limit() -> None:
     asyncio.run(provider.create_response(_response("resp_lim"), many_inputs, None))
 
     ids = asyncio.run(provider.get_history_item_ids("resp_lim", None, 3))
-    assert len(ids) == 3
+    assert ids == ["in_lim_7", "in_lim_8", "in_lim_9"]
 
 
 def test_history__zero_limit_returns_empty() -> None: